DC current sensor

Abstract

A DC current sensor with an exciting core of soft magnetic material and formed with a pair of tubular bodies, each tubular body being positioned in parallel with the other to provide therebetween a space, through which passes a wire conducting a current to be detected; a detecting core formed with the side faces of a pair of tubular bodies and two plate-like members of soft magnetic material, each of which connecting integrally with each of the inside edges thereof near an opening of the tubular bodies to form a rectangular frame-shaped member as a whole; exciting coils, each of which magnetically energizing the exciting core in the direction perpendicular to the plane of the detecting core; detecting coils, each of which being wound around the detecting core; and applying an alternating current to the exciting coils to periodically and magnetically saturate the rectangular-shaped portions of the detecting core and exciting core, energizing the exciting coils to modulate a magnetic flux produced in the detecting core corresponding to the DC current flowing through the wire.

What is claimed is: 
     
       1. A DC current sensor, comprising an exciting core of soft magnetic material and formed with a pair of tubular bodies, each tubular body being positioned in parallel with the other to provide therebetween a space, through which passes a wire conducting a current to be detected;   a detecting core formed with the side faces of a pair of tubular bodies and two plate-like members of soft magnetic material, each of which connecting integrally with each of the inside edges thereof near an opening of said tubular bodies to form a rectangular frame-shaped member as a whole;   exciting coils, each of which magnetically energizing the exciting core in the direction perpendicular to the plane of the detecting core;   detecting coils, each of which being wound around said detecting core; and   means for applying an alternating current to the exciting coils to periodically and magnetically saturate the rectangular-shaped portions of said detecting core and exciting core, said means energizing said exciting coils to modulate a magnetic flux produced in the detecting core corresponding to the DC current flowing through said wire.   
     
     
       2. A DC current sensor according to claim 1, wherein the exciting coil is wound around the outside wall surface of the tubular body in the lengthwise direction thereof. 
     
     
       3. A DC current sensor according to claim 1, wherein each of said tubular bodies is provided inside thereof with a mid-shelf extending in the axial direction of the square tubular body, and the exciting coil is wound around said mid-shelf. 
     
     
       4. A DC current sensor according to claim 1, wherein the exciting coil is wound around the detecting core. 
     
     
       5. A DC current sensor according to claim 1, wherein the detecting coil is wound toroidally around each of the opposed side walls of the rectangular frame-shaped detecting core. 
     
     
       6. A DC current sensor according to claim 1, wherein the detecting core is composed of separable members.